docs: def contribute_to_related_class(self, cls, related):
          """
          Override ForeignKey's methods, and replace the descriptor, if set by
          the parent's methods
          """
          # Internal FK's - i.e., those with a related name ending with '+' -
          # and swapped models don't get a related descriptor.
          super(VersionedForeignKey, self).contribute_to_related_class(cls,
                                                                       related)
          accessor_name = related.get_accessor_name()
          if hasattr(cls, accessor_name):
              setattr(cls, accessor_name,
                      VersionedReverseManyToOneDescriptor(related))